“The problem is that water is a finite resource,” says Glennon. “Water that’s in our aquifers took mother nature hundreds or sometimes thousands of years to accumulate, but in many instances we’re pumping it out in mere decades.” Some demands on water are frivolous, he says, such as bottled water and high-volume showers, but many demands are important.

“The requirements of water for producing energy are enormous,” says Glennon. America needs so much energy, he says, and sustainable energies require water during processing. “We’re not going to produce more H2O,” he says. “What we have, we have; we’re drinking the same water as the dinosaurs.”

In Los Angeles, for example, each time a toilet empties, six gallons of water enter the ocean and the hydrologic cycle, he says, making that water unavailable for hundreds of years. “The water isn’t where we need it, when we need it, in the form that we need it.”

“Think of our public supply as a giant milkshake glass, and think of each demand as a straw in the glass,” says Glennon. “If you want to put a new straw in that glass, you need to persuade someone else to take her straw out of the glass.”

Cities, industries and developers are beginning to pay farmers to modernize and improve their irrigation efficiency, he says. Over 50 percent of irrigation in the U.S. is accomplished through flood irrigation, which is the least efficient form of irrigation. “There are a lot of ways to use the water better.”

“The idea of a fountain in the middle of the Mojave Desert,” he says, “is pretty bizarre.” However, all of the water on the Las Vegas strip is recycled, Glennon says, only using 3 percent of the city’s water supply. The city has spent millions of dollars paying citizens to convert turf into xeriscaping, or native vegetation, to decrease the use of water, says Glennon.

Arizona, Glennon’s home state, is taking steps to preserve water through water reuse, water recharging, water banking, and water harvesting. “You’ll seldom see a lawn, you’ll see rain harvesting barrels, you’ll see xeriscaping,” says Glennon. “It’s just really in the DNA of the city of Tucson now.”

Michigan still does not have control of how much groundwater is being pumped out of the water table, he says. “In the last year, there have been permits given out for over 600 commercial-scale wells,” says Glennon. Many farmers are responding to the recent droughts with a need for irrigation, he says. “You cannot let there be such open access to a finite resource.

The national water policy is even worse than the national energy policy, Glennon says. “National trade policy,” he says, “encourages farmers to send water to China in the form of bales of alfalfa, but simultaneously prohibits those farmers from selling the water to nearby Las Vegas.”

To save water each day, stop using the kitchen food disposal, which he says can use 150 gallons of water each month. Another water-guzzling culprit is the 60-watt incandescent bulb, says Glennon, which if burning 12 hours each day, can use as much as 6,300 gallons of water each year.

“If we we’re serious about conserving water, let’s turn off some lights.”